1. Field of the Invention
This invention relates to materials handling apparatus and, more specifically, to a combination bulldozer blade and materials handling bucket having ejector capability for earth moving operations and which may also be optionally provided with forklift capability and other general haulage capability.
2. Description of the Prior Art
A number of skid shovel and scoop shovel machines are manufactured or disclosed in patents for earth moving operations both underground, as in mining or tunneling, or above ground, as in strip mining or other earth stripping operations. Frequently, such machines are specifically designed to provide a multiplicity or other useful functions, such as bulldozing, scraper operations, clamshell operations and, on occasion, general demolition functions. Typical such machines are disclosed in U.S. Pat. Nos.
______________________________________ 2,812,595 2,924,345 3,077,999 3,148,787 3,250,128 3,252,606 3,296,720 3,334,430 3,346,974 3,477,602 3,542,223 3,842,999 3,921,316 ______________________________________
Generally, skid shovel and scoop shovel machines per se, function adequately as earth transportation machines, so long as another machine, such as a bulldozer, is available to excavate or initially remove and pile up the material to be transported thereby. However, by reason of the very nature of the basic design of skid shovel and scoop shovel machines, they do not function efficiently to initially excavate the material to be transported and, accordingly, their transportation efficiency is seriously diminished. Moreover, in certain environments, such as underground mining operations, where available working height is limited, the design mode of operation of these machines add additional limitations, particularly when they are outfitted with additional equipment provided to render the machine multifunctional, such as providing one or more of the additional functions mentioned above.
Keeping in mind that, for a multitude of earth moving operations, the principal functions of earth removal or excavation combined with earth collection and transportation, at a maximum potential capacity in a minimum amount of time, are of paramount interest, no known skid shovel or scoop shovel machine performs fully to these desiderata. In particular, the bulldozing of loose earth material into a pile cannot generally be efficiently done by the buckets of skid shovel and scoop shovel machines. The loose material tends to roll along and then slip under the bucket's leading edge. Moreover, in order to get the earth material into the bucket without assistance from other machines, the operators tram the machines at maximum, attempting to force the material rearwardly the full length or extent of the bucket bottom. However, only partial loads are possible by this operation considering the full available volume of the bucket. Of course, the shock loads on the vehicle are very destructive of the entire vehicle structure. Furthermore, if the skid or scoop bucket is used as a primary haulage unit, its productivity is extremely limited due to the small loads being transported. Accordingly, there is a need for improvements in earth moving machines of the type discussed so as to provide for earth removal or excavation combined with earth collection and transportation, at maximum potential capacity in a minimum amount of time, in order to greatly enhance productivity and machine utilization.